Pitched Gable Roof

[Jon87]

Hi guys,

I'm hoping someone can point me in the right direction for information regarding how a gable pitched roof attaches to a flat wall. Also if the ridge beam can be made of wood for a 6m extension or if a steel is needed?

Hopefully someone can help,
Jon

 

[^woody^]

Wall plate.

Are you referring to a ridge board where the roof has a loft below it, or a ridge beam where there is room below it?

 

[Jon87]

Ridge beam, it's going to be a single story extension.

 

[Leofric]

depends how much the ridge beam is supporting - pitch of roof/width of extension/ size of ridge beam. 6m probably steel beam .

 

[Jon87]

Yeah I'm hoping that I won't need a steel to keep costs down, but thanks for the help so far guys.

If it's a wooden ridge beam, does anyone know where I can find detail drawing/images of the wall plates, struggling to find many examples?

 

[^woody^]

Don't you have some plans to work off?

There are probably 50 million pictures of wall plates in a Google image search. Give it a try.

 

[Leofric]

Not sure what you are asking, rafter feet sit on the wallplates

 

[Jon87]

Ah ok let me try and explain. So I understand pitched roofs use horizontal wall plates bolted to the wall as seen below (ignore the colourful arrows)

But for a Gable roof, are the rafters closest to the wall bolted into the wall similar to wall plates?

I was also curious how the Ridge Beam would be fixed into the wall if it was wood and not a steel beam. Im presuming using joist hangers but I wasnt sure?

 

[23vc]

No the rafters are not fixed to the wall. Ridge Beam built into brickwork

 

[garyo]

6m is quite a span. What is your roof cover ? Concrete tiles?

A single steel isn't that expensive given that you'll want some calculations anyway, but they can increase your labour time.

Are you doing this DIY? There was a chap on TV that used back to back steel channel bolted together rather rather than UB so than individual pieces could be manhandled into place and therefore save on crane costs. I've never heard of that before, and surprised it makes that much difference.

 

[garyo]

I was also curious how the Ridge Beam would be fixed into the wall if it was wood and not a steel beam. Im presuming using joist hangers but I wasnt sure?

Have a browse through nosealls gallery. He has some good shots of vaulted roof frames with steel ridges that will give you an idea of what you're getting in to.

As 23cv says, you'd build the ridge beam into the gable at each end and may or may not need padstones depending on load and density of your wall blocks.

 

[datarebal]

if i read this correctly . A timber rige board can be any length... subject to roof weight and ceiling design.
certainly we have re slated an old building 50 mtrs in length all timber no steels and 150 years old..

 

[garyo]

if i read this correctly . A timber rige board can be any length... subject to roof weight and ceiling design.
certainly we have re slated an old building 50 mtrs in length all timber no steels and 150 years old..

I read his requirement as a beam - a vaulted ceiling with no joists tying the rafter feet together. Having said that, purlins haven't been mentioned yet.

 

[Notch7]

Yeah I'm hoping that I won't need a steel to keep costs down, but thanks for the help so far guys.

If it's a wooden ridge beam, does anyone know where I can find detail drawing/images of the wall plates, struggling to find many examples?

the question we need to know is whether the roof is vaulted or will be flat.
If the ceiling internally is flat then there will be ceiling joists which stop the roof spreading. Such a roof needs only a small timber ridge -its not taking any load

If the ceiling is vaulted then you need a structural ridge that supports the weight of the roof and prevents the roof spreading.
The ridge will then need to be supported at each end to take the load.

 

[23vc]

the question we need to know is whether the roof is vaulted or will be flat.
If the ceiling internally is flat then there will be ceiling joists which stop the roof spreading. Such a roof needs only a small timber ridge -its not taking any load

If the ceiling is vaulted then you need a structural ridge that supports the weight of the roof and prevents the roof spreading.
The ridge will then need to be supported at each end to take the load.

you might still have a flat ceiling but need a ridge beam because the ceiling joist span is too long.